uDOS is a free operating system built on the FreeDOS kernel with DJGPP. uDOS provides an integrated suite of features inluding Perl, Python, etc., as well as a Watt-32 based networking environment and ELF library support. Can be run live from CD image.

FreeOS/1 is a Free, Open Source, FreeDOS based Free and Open Source Alternative OS, with open source Microsoft Windows compatibility using HXDOSExtender KernelEx,and ReactOS source code. FreeOS/1 will include new technologies and will be easy to use